Struct memory limit

Question

I have a question about struct in C++. Actually, my code was something like this

struct SegmentTree {
    int segmentTree[2500000];

    some functions...
}

When I compiled it, it was giving me a segmentation fault immediately, but when I tried to do the same thing with class, everything worked well. So, my question: Is there some limited number of variables that I can use in a struct, or else, what's the problem?

Answer 1

An array declared like this will be allocated on the stack(same as with local variables for functions). The limit of the number of elements in a static array is defined by your stack size(which can be modified using compiler options). Consider using dynamically allocated array(or even better std::vector) to make use of the heap instead.